Unaudited Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred stock:	Common stock:	Additional paid-in capital:	Retained earnings:	Accumulated other comprehensive income (loss):	Treasury stock:
Beginning of period at Dec. 31, 2022		$ 200,000	$ 209,694	$ 493,488	$ 2,749,703	$ (498,042)	$ (627,279)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		0
Dividend reinvestment plan			19	908
Stock purchase and compensation plans			583	17,644
Net income (loss)	$ 151,182				151,182
Dividends to preferred stockholders					(4,600)
Dividends to common stockholders					(36,716)
Other comprehensive income (loss)	22,320					22,320
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans							(7,512)
End of period at Jun. 30, 2023	$ 2,671,392	$ 200,000	210,296	512,040	2,859,569	(475,722)	(634,791)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per preferred share (in dollars per share)	$ 575.00
Dividends declared per common share (in dollars per share)	$ 0.60
Preferred stock, shares outstanding, beginning balance (in shares) at Dec. 31, 2022	8,000
Preferred stock, shares outstanding:
Issuance of preferred stock (in shares)		0
Preferred stock, shares outstanding, ending balance (in shares) at Jun. 30, 2023	8,000
Common stock, shares outstanding, beginning of period (in shares) at Dec. 31, 2022	60,338,900
Common stock, shares outstanding:
Dividend reinvestment plan (in shares)	9,315
Stock purchase and compensation plan (in shares)	291,739
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans (in shares)	(74,471)
Common stock, shares outstanding, end of period (in shares) at Jun. 30, 2023	60,565,483
Beginning of period at Mar. 31, 2023		$ 200,000	210,149	502,713	2,821,613	(430,349)	(634,722)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		0
Dividend reinvestment plan			10	449
Stock purchase and compensation plans			137	8,878
Net income (loss)	$ 58,608				58,608
Dividends to preferred stockholders					(2,300)
Dividends to common stockholders					(18,352)
Other comprehensive income (loss)	(45,373)					(45,373)
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans							(69)
End of period at Jun. 30, 2023	$ 2,671,392	$ 200,000	210,296	512,040	2,859,569	(475,722)	(634,791)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per preferred share (in dollars per share)	$ 287.50
Dividends declared per common share (in dollars per share)	$ 0.30
Preferred stock, shares outstanding, beginning balance (in shares) at Mar. 31, 2023	8,000
Preferred stock, shares outstanding:
Issuance of preferred stock (in shares)		0
Preferred stock, shares outstanding, ending balance (in shares) at Jun. 30, 2023	8,000
Common stock, shares outstanding, beginning of period (in shares) at Mar. 31, 2023	60,492,586
Common stock, shares outstanding:
Dividend reinvestment plan (in shares)	4,665
Stock purchase and compensation plan (in shares)	68,923
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans (in shares)	(691)
Common stock, shares outstanding, end of period (in shares) at Jun. 30, 2023	60,565,483
Beginning of period at Dec. 31, 2023	$ 2,954,381	$ 200,000	210,447	522,748	3,029,396	(373,001)	(635,209)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		0
Dividend reinvestment plan			20	972
Stock purchase and compensation plans			565	21,543
Net income (loss)	19,199				19,199
Dividends to preferred stockholders					(4,600)
Dividends to common stockholders					(42,941)
Other comprehensive income (loss)	(19,720)					(19,720)
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans							(6,728)
End of period at Jun. 30, 2024	$ 2,922,691	$ 200,000	211,032	545,263	3,001,054	(392,721)	(641,937)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per preferred share (in dollars per share)	$ 575.00
Dividends declared per common share (in dollars per share)	$ 0.70
Preferred stock, shares outstanding, beginning balance (in shares) at Dec. 31, 2023	8,000
Preferred stock, shares outstanding:
Issuance of preferred stock (in shares)		0
Preferred stock, shares outstanding, ending balance (in shares) at Jun. 30, 2024	8,000
Common stock, shares outstanding, beginning of period (in shares) at Dec. 31, 2023	60,636,437
Common stock, shares outstanding:
Dividend reinvestment plan (in shares)	9,959
Stock purchase and compensation plan (in shares)	282,928
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans (in shares)	(69,376)
Common stock, shares outstanding, end of period (in shares) at Jun. 30, 2024	60,859,948
Beginning of period at Mar. 31, 2024		$ 200,000	210,895	534,327	3,088,150	(384,972)	(641,906)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		0
Dividend reinvestment plan			10	484
Stock purchase and compensation plans			127	10,452
Net income (loss)	$ (63,319)				(63,319)
Dividends to preferred stockholders					(2,300)
Dividends to common stockholders					(21,477)
Other comprehensive income (loss)	(7,749)					(7,749)
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans							(31)
End of period at Jun. 30, 2024	$ 2,922,691	$ 200,000	$ 211,032	$ 545,263	$ 3,001,054	$ (392,721)	$ (641,937)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per preferred share (in dollars per share)	$ 287.50
Dividends declared per common share (in dollars per share)	$ 0.35
Preferred stock, shares outstanding, beginning balance (in shares) at Mar. 31, 2024	8,000
Preferred stock, shares outstanding:
Issuance of preferred stock (in shares)		0
Preferred stock, shares outstanding, ending balance (in shares) at Jun. 30, 2024	8,000
Common stock, shares outstanding, beginning of period (in shares) at Mar. 31, 2024	60,791,439
Common stock, shares outstanding:
Dividend reinvestment plan (in shares)	5,153
Stock purchase and compensation plan (in shares)	63,664
Acquisition of treasury stock - shares acquired related to employee share-based compensation plans (in shares)	(308)
Common stock, shares outstanding, end of period (in shares) at Jun. 30, 2024	60,859,948